Does anyone know what the procedure is in federal courts after a sentence is vacated and remanded by the appellate court? How long do they have to send some one back from prison to the district court? What about a motion being filed by the federal district court against the decision of the appellate court ? What happens to the prisoner then? Does he stay in prison or go back to the district jail?

the remand is a great and rare thing. His attorney will file for a date and then the Marshals will bring him back. The court doesn't file motions only defense and prosecution...and they have already filed, unless they are taking it to the Supreme court. I expect he will stay put until the hearing is set. Congratulations, assuming it was a defense motion that got him remanded, hopefully it will be good news.